xref: /openbmc/qemu/qemu-nbd.c (revision 14a48c1d)
1 /*
2  *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
3  *
4  *  Network Block Device
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; under version 2 of the License.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "qemu/osdep.h"
20 #include <getopt.h>
21 #include <libgen.h>
22 #include <pthread.h>
23 
24 #include "qemu-common.h"
25 #include "qapi/error.h"
26 #include "qemu/cutils.h"
27 #include "sysemu/block-backend.h"
28 #include "block/block_int.h"
29 #include "block/nbd.h"
30 #include "qemu/main-loop.h"
31 #include "qemu/option.h"
32 #include "qemu/error-report.h"
33 #include "qemu/config-file.h"
34 #include "qemu/bswap.h"
35 #include "qemu/log.h"
36 #include "qemu/systemd.h"
37 #include "block/snapshot.h"
38 #include "qapi/qmp/qdict.h"
39 #include "qapi/qmp/qstring.h"
40 #include "qom/object_interfaces.h"
41 #include "io/channel-socket.h"
42 #include "io/net-listener.h"
43 #include "crypto/init.h"
44 #include "trace/control.h"
45 #include "qemu-version.h"
46 
47 #ifdef __linux__
48 #define HAVE_NBD_DEVICE 1
49 #else
50 #define HAVE_NBD_DEVICE 0
51 #endif
52 
53 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
54 #define QEMU_NBD_OPT_CACHE         256
55 #define QEMU_NBD_OPT_AIO           257
56 #define QEMU_NBD_OPT_DISCARD       258
57 #define QEMU_NBD_OPT_DETECT_ZEROES 259
58 #define QEMU_NBD_OPT_OBJECT        260
59 #define QEMU_NBD_OPT_TLSCREDS      261
60 #define QEMU_NBD_OPT_IMAGE_OPTS    262
61 #define QEMU_NBD_OPT_FORK          263
62 #define QEMU_NBD_OPT_TLSAUTHZ      264
63 
64 #define MBR_SIZE 512
65 
66 static NBDExport *export;
67 static int verbose;
68 static char *srcpath;
69 static SocketAddress *saddr;
70 static int persistent = 0;
71 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
72 static int shared = 1;
73 static int nb_fds;
74 static QIONetListener *server;
75 static QCryptoTLSCreds *tlscreds;
76 static const char *tlsauthz;
77 
78 static void usage(const char *name)
79 {
80     (printf) (
81 "Usage: %s [OPTIONS] FILE\n"
82 "  or:  %s -L [OPTIONS]\n"
83 "QEMU Disk Network Block Device Utility\n"
84 "\n"
85 "  -h, --help                display this help and exit\n"
86 "  -V, --version             output version information and exit\n"
87 "\n"
88 "Connection properties:\n"
89 "  -p, --port=PORT           port to listen on (default `%d')\n"
90 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
91 "  -k, --socket=PATH         path to the unix socket\n"
92 "                            (default '"SOCKET_PATH"')\n"
93 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
94 "  -t, --persistent          don't exit on the last connection\n"
95 "  -v, --verbose             display extra debugging information\n"
96 "  -x, --export-name=NAME    expose export by name (default is empty string)\n"
97 "  -D, --description=TEXT    export a human-readable description\n"
98 "\n"
99 "Exposing part of the image:\n"
100 "  -o, --offset=OFFSET       offset into the image\n"
101 "  -P, --partition=NUM       only expose partition NUM\n"
102 "  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
103 "\n"
104 "General purpose options:\n"
105 "  -L, --list                list exports available from another NBD server\n"
106 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
107 "                            passwords and/or encryption keys\n"
108 "  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
109 "  --tls-authz=ID            use id of an earlier --object to provide\n"
110 "                            authorization\n"
111 "  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
112 "                            specify tracing options\n"
113 "  --fork                    fork off the server process and exit the parent\n"
114 "                            once the server is running\n"
115 #if HAVE_NBD_DEVICE
116 "\n"
117 "Kernel NBD client support:\n"
118 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
119 "  -d, --disconnect          disconnect the specified device\n"
120 #endif
121 "\n"
122 "Block device options:\n"
123 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
124 "  -r, --read-only           export read-only\n"
125 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
126 "                            file with backing_file=FILE, redirect the write to\n"
127 "                            the temporary one\n"
128 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
129 "                            load an internal snapshot inside FILE and export it\n"
130 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
131 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
132 "                            '[ID_OR_NAME]'\n"
133 "  -n, --nocache             disable host cache\n"
134 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
135 "      --aio=MODE            set AIO mode (native or threads)\n"
136 "      --discard=MODE        set discard mode (ignore, unmap)\n"
137 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
138 "      --image-opts          treat FILE as a full set of image options\n"
139 "\n"
140 QEMU_HELP_BOTTOM "\n"
141     , name, name, NBD_DEFAULT_PORT, "DEVICE");
142 }
143 
144 static void version(const char *name)
145 {
146     printf(
147 "%s " QEMU_FULL_VERSION "\n"
148 "Written by Anthony Liguori.\n"
149 "\n"
150 QEMU_COPYRIGHT "\n"
151 "This is free software; see the source for copying conditions.  There is NO\n"
152 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
153     , name);
154 }
155 
156 struct partition_record
157 {
158     uint8_t bootable;
159     uint8_t start_head;
160     uint32_t start_cylinder;
161     uint8_t start_sector;
162     uint8_t system;
163     uint8_t end_head;
164     uint8_t end_cylinder;
165     uint8_t end_sector;
166     uint32_t start_sector_abs;
167     uint32_t nb_sectors_abs;
168 };
169 
170 static void read_partition(uint8_t *p, struct partition_record *r)
171 {
172     r->bootable = p[0];
173     r->start_head = p[1];
174     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
175     r->start_sector = p[2] & 0x3f;
176     r->system = p[4];
177     r->end_head = p[5];
178     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
179     r->end_sector = p[6] & 0x3f;
180 
181     r->start_sector_abs = ldl_le_p(p + 8);
182     r->nb_sectors_abs   = ldl_le_p(p + 12);
183 }
184 
185 static int find_partition(BlockBackend *blk, int partition,
186                           uint64_t *offset, uint64_t *size)
187 {
188     struct partition_record mbr[4];
189     uint8_t data[MBR_SIZE];
190     int i;
191     int ext_partnum = 4;
192     int ret;
193 
194     ret = blk_pread(blk, 0, data, sizeof(data));
195     if (ret < 0) {
196         error_report("error while reading: %s", strerror(-ret));
197         exit(EXIT_FAILURE);
198     }
199 
200     if (data[510] != 0x55 || data[511] != 0xaa) {
201         return -EINVAL;
202     }
203 
204     for (i = 0; i < 4; i++) {
205         read_partition(&data[446 + 16 * i], &mbr[i]);
206 
207         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
208             continue;
209         }
210 
211         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
212             struct partition_record ext[4];
213             uint8_t data1[MBR_SIZE];
214             int j;
215 
216             ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE,
217                             data1, sizeof(data1));
218             if (ret < 0) {
219                 error_report("error while reading: %s", strerror(-ret));
220                 exit(EXIT_FAILURE);
221             }
222 
223             for (j = 0; j < 4; j++) {
224                 read_partition(&data1[446 + 16 * j], &ext[j]);
225                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
226                     continue;
227                 }
228 
229                 if ((ext_partnum + j + 1) == partition) {
230                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
231                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
232                     return 0;
233                 }
234             }
235             ext_partnum += 4;
236         } else if ((i + 1) == partition) {
237             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
238             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
239             return 0;
240         }
241     }
242 
243     return -ENOENT;
244 }
245 
246 static void termsig_handler(int signum)
247 {
248     atomic_cmpxchg(&state, RUNNING, TERMINATE);
249     qemu_notify_event();
250 }
251 
252 
253 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
254                                 const char *hostname)
255 {
256     int ret = EXIT_FAILURE;
257     int rc;
258     Error *err = NULL;
259     QIOChannelSocket *sioc;
260     NBDExportInfo *list;
261     int i, j;
262 
263     sioc = qio_channel_socket_new();
264     if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
265         error_report_err(err);
266         return EXIT_FAILURE;
267     }
268     rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
269                                  &err);
270     if (rc < 0) {
271         if (err) {
272             error_report_err(err);
273         }
274         goto out;
275     }
276     printf("exports available: %d\n", rc);
277     for (i = 0; i < rc; i++) {
278         printf(" export: '%s'\n", list[i].name);
279         if (list[i].description && *list[i].description) {
280             printf("  description: %s\n", list[i].description);
281         }
282         if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
283             static const char *const flag_names[] = {
284                 [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
285                 [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
286                 [NBD_FLAG_SEND_FUA_BIT]             = "fua",
287                 [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
288                 [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
289                 [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
290                 [NBD_FLAG_SEND_DF_BIT]              = "df",
291                 [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
292                 [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
293                 [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
294             };
295 
296             printf("  size:  %" PRIu64 "\n", list[i].size);
297             printf("  flags: 0x%x (", list[i].flags);
298             for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
299                 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
300                     printf(" %s", flag_names[bit]);
301                 }
302             }
303             printf(" )\n");
304         }
305         if (list[i].min_block) {
306             printf("  min block: %u\n", list[i].min_block);
307             printf("  opt block: %u\n", list[i].opt_block);
308             printf("  max block: %u\n", list[i].max_block);
309         }
310         if (list[i].n_contexts) {
311             printf("  available meta contexts: %d\n", list[i].n_contexts);
312             for (j = 0; j < list[i].n_contexts; j++) {
313                 printf("   %s\n", list[i].contexts[j]);
314             }
315         }
316     }
317     nbd_free_export_list(list, rc);
318 
319     ret = EXIT_SUCCESS;
320  out:
321     object_unref(OBJECT(sioc));
322     return ret;
323 }
324 
325 
326 #if HAVE_NBD_DEVICE
327 static void *show_parts(void *arg)
328 {
329     char *device = arg;
330     int nbd;
331 
332     /* linux just needs an open() to trigger
333      * the partition table update
334      * but remember to load the module with max_part != 0 :
335      *     modprobe nbd max_part=63
336      */
337     nbd = open(device, O_RDWR);
338     if (nbd >= 0) {
339         close(nbd);
340     }
341     return NULL;
342 }
343 
344 static void *nbd_client_thread(void *arg)
345 {
346     char *device = arg;
347     NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
348     QIOChannelSocket *sioc;
349     int fd;
350     int ret;
351     pthread_t show_parts_thread;
352     Error *local_error = NULL;
353 
354     sioc = qio_channel_socket_new();
355     if (qio_channel_socket_connect_sync(sioc,
356                                         saddr,
357                                         &local_error) < 0) {
358         error_report_err(local_error);
359         goto out;
360     }
361 
362     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc),
363                                 NULL, NULL, NULL, &info, &local_error);
364     if (ret < 0) {
365         if (local_error) {
366             error_report_err(local_error);
367         }
368         goto out_socket;
369     }
370 
371     fd = open(device, O_RDWR);
372     if (fd < 0) {
373         /* Linux-only, we can use %m in printf.  */
374         error_report("Failed to open %s: %m", device);
375         goto out_socket;
376     }
377 
378     ret = nbd_init(fd, sioc, &info, &local_error);
379     if (ret < 0) {
380         error_report_err(local_error);
381         goto out_fd;
382     }
383 
384     /* update partition table */
385     pthread_create(&show_parts_thread, NULL, show_parts, device);
386 
387     if (verbose) {
388         fprintf(stderr, "NBD device %s is now connected to %s\n",
389                 device, srcpath);
390     } else {
391         /* Close stderr so that the qemu-nbd process exits.  */
392         dup2(STDOUT_FILENO, STDERR_FILENO);
393     }
394 
395     ret = nbd_client(fd);
396     if (ret) {
397         goto out_fd;
398     }
399     close(fd);
400     object_unref(OBJECT(sioc));
401     g_free(info.name);
402     kill(getpid(), SIGTERM);
403     return (void *) EXIT_SUCCESS;
404 
405 out_fd:
406     close(fd);
407 out_socket:
408     object_unref(OBJECT(sioc));
409 out:
410     g_free(info.name);
411     kill(getpid(), SIGTERM);
412     return (void *) EXIT_FAILURE;
413 }
414 #endif /* HAVE_NBD_DEVICE */
415 
416 static int nbd_can_accept(void)
417 {
418     return state == RUNNING && nb_fds < shared;
419 }
420 
421 static void nbd_export_closed(NBDExport *export)
422 {
423     assert(state == TERMINATING);
424     state = TERMINATED;
425 }
426 
427 static void nbd_update_server_watch(void);
428 
429 static void nbd_client_closed(NBDClient *client, bool negotiated)
430 {
431     nb_fds--;
432     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
433         state = TERMINATE;
434     }
435     nbd_update_server_watch();
436     nbd_client_put(client);
437 }
438 
439 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
440                        gpointer opaque)
441 {
442     if (state >= TERMINATE) {
443         return;
444     }
445 
446     nb_fds++;
447     nbd_update_server_watch();
448     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
449 }
450 
451 static void nbd_update_server_watch(void)
452 {
453     if (nbd_can_accept()) {
454         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
455     } else {
456         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
457     }
458 }
459 
460 
461 static SocketAddress *nbd_build_socket_address(const char *sockpath,
462                                                const char *bindto,
463                                                const char *port)
464 {
465     SocketAddress *saddr;
466 
467     saddr = g_new0(SocketAddress, 1);
468     if (sockpath) {
469         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
470         saddr->u.q_unix.path = g_strdup(sockpath);
471     } else {
472         InetSocketAddress *inet;
473         saddr->type = SOCKET_ADDRESS_TYPE_INET;
474         inet = &saddr->u.inet;
475         inet->host = g_strdup(bindto);
476         if (port) {
477             inet->port = g_strdup(port);
478         } else  {
479             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
480         }
481     }
482 
483     return saddr;
484 }
485 
486 
487 static QemuOptsList file_opts = {
488     .name = "file",
489     .implied_opt_name = "file",
490     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
491     .desc = {
492         /* no elements => accept any params */
493         { /* end of list */ }
494     },
495 };
496 
497 static QemuOptsList qemu_object_opts = {
498     .name = "object",
499     .implied_opt_name = "qom-type",
500     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
501     .desc = {
502         { }
503     },
504 };
505 
506 
507 
508 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
509                                           Error **errp)
510 {
511     Object *obj;
512     QCryptoTLSCreds *creds;
513 
514     obj = object_resolve_path_component(
515         object_get_objects_root(), id);
516     if (!obj) {
517         error_setg(errp, "No TLS credentials with id '%s'",
518                    id);
519         return NULL;
520     }
521     creds = (QCryptoTLSCreds *)
522         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
523     if (!creds) {
524         error_setg(errp, "Object with id '%s' is not TLS credentials",
525                    id);
526         return NULL;
527     }
528 
529     if (list) {
530         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
531             error_setg(errp,
532                        "Expecting TLS credentials with a client endpoint");
533             return NULL;
534         }
535     } else {
536         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
537             error_setg(errp,
538                        "Expecting TLS credentials with a server endpoint");
539             return NULL;
540         }
541     }
542     object_ref(obj);
543     return creds;
544 }
545 
546 static void setup_address_and_port(const char **address, const char **port)
547 {
548     if (*address == NULL) {
549         *address = "0.0.0.0";
550     }
551 
552     if (*port == NULL) {
553         *port = stringify(NBD_DEFAULT_PORT);
554     }
555 }
556 
557 /*
558  * Check socket parameters compatibility when socket activation is used.
559  */
560 static const char *socket_activation_validate_opts(const char *device,
561                                                    const char *sockpath,
562                                                    const char *address,
563                                                    const char *port,
564                                                    bool list)
565 {
566     if (device != NULL) {
567         return "NBD device can't be set when using socket activation";
568     }
569 
570     if (sockpath != NULL) {
571         return "Unix socket can't be set when using socket activation";
572     }
573 
574     if (address != NULL) {
575         return "The interface can't be set when using socket activation";
576     }
577 
578     if (port != NULL) {
579         return "TCP port number can't be set when using socket activation";
580     }
581 
582     if (list) {
583         return "List mode is incompatible with socket activation";
584     }
585 
586     return NULL;
587 }
588 
589 static void qemu_nbd_shutdown(void)
590 {
591     job_cancel_sync_all();
592     bdrv_close_all();
593 }
594 
595 int main(int argc, char **argv)
596 {
597     BlockBackend *blk;
598     BlockDriverState *bs;
599     uint64_t dev_offset = 0;
600     uint16_t nbdflags = 0;
601     bool disconnect = false;
602     const char *bindto = NULL;
603     const char *port = NULL;
604     char *sockpath = NULL;
605     char *device = NULL;
606     int64_t fd_size;
607     QemuOpts *sn_opts = NULL;
608     const char *sn_id_or_name = NULL;
609     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:L";
610     struct option lopt[] = {
611         { "help", no_argument, NULL, 'h' },
612         { "version", no_argument, NULL, 'V' },
613         { "bind", required_argument, NULL, 'b' },
614         { "port", required_argument, NULL, 'p' },
615         { "socket", required_argument, NULL, 'k' },
616         { "offset", required_argument, NULL, 'o' },
617         { "read-only", no_argument, NULL, 'r' },
618         { "partition", required_argument, NULL, 'P' },
619         { "bitmap", required_argument, NULL, 'B' },
620         { "connect", required_argument, NULL, 'c' },
621         { "disconnect", no_argument, NULL, 'd' },
622         { "list", no_argument, NULL, 'L' },
623         { "snapshot", no_argument, NULL, 's' },
624         { "load-snapshot", required_argument, NULL, 'l' },
625         { "nocache", no_argument, NULL, 'n' },
626         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
627         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
628         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
629         { "detect-zeroes", required_argument, NULL,
630           QEMU_NBD_OPT_DETECT_ZEROES },
631         { "shared", required_argument, NULL, 'e' },
632         { "format", required_argument, NULL, 'f' },
633         { "persistent", no_argument, NULL, 't' },
634         { "verbose", no_argument, NULL, 'v' },
635         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
636         { "export-name", required_argument, NULL, 'x' },
637         { "description", required_argument, NULL, 'D' },
638         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
639         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
640         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
641         { "trace", required_argument, NULL, 'T' },
642         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
643         { NULL, 0, NULL, 0 }
644     };
645     int ch;
646     int opt_ind = 0;
647     int flags = BDRV_O_RDWR;
648     int partition = 0;
649     int ret = 0;
650     bool seen_cache = false;
651     bool seen_discard = false;
652     bool seen_aio = false;
653     pthread_t client_thread;
654     const char *fmt = NULL;
655     Error *local_err = NULL;
656     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
657     QDict *options = NULL;
658     const char *export_name = NULL; /* defaults to "" later for server mode */
659     const char *export_description = NULL;
660     const char *bitmap = NULL;
661     const char *tlscredsid = NULL;
662     bool imageOpts = false;
663     bool writethrough = true;
664     char *trace_file = NULL;
665     bool fork_process = false;
666     bool list = false;
667     int old_stderr = -1;
668     unsigned socket_activation;
669 
670     /* The client thread uses SIGTERM to interrupt the server.  A signal
671      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
672      */
673     struct sigaction sa_sigterm;
674     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
675     sa_sigterm.sa_handler = termsig_handler;
676     sigaction(SIGTERM, &sa_sigterm, NULL);
677 
678 #ifdef CONFIG_POSIX
679     signal(SIGPIPE, SIG_IGN);
680 #endif
681 
682     error_init(argv[0]);
683     module_call_init(MODULE_INIT_TRACE);
684     qcrypto_init(&error_fatal);
685 
686     module_call_init(MODULE_INIT_QOM);
687     qemu_add_opts(&qemu_object_opts);
688     qemu_add_opts(&qemu_trace_opts);
689     qemu_init_exec_dir(argv[0]);
690 
691     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
692         switch (ch) {
693         case 's':
694             flags |= BDRV_O_SNAPSHOT;
695             break;
696         case 'n':
697             optarg = (char *) "none";
698             /* fallthrough */
699         case QEMU_NBD_OPT_CACHE:
700             if (seen_cache) {
701                 error_report("-n and --cache can only be specified once");
702                 exit(EXIT_FAILURE);
703             }
704             seen_cache = true;
705             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
706                 error_report("Invalid cache mode `%s'", optarg);
707                 exit(EXIT_FAILURE);
708             }
709             break;
710         case QEMU_NBD_OPT_AIO:
711             if (seen_aio) {
712                 error_report("--aio can only be specified once");
713                 exit(EXIT_FAILURE);
714             }
715             seen_aio = true;
716             if (!strcmp(optarg, "native")) {
717                 flags |= BDRV_O_NATIVE_AIO;
718             } else if (!strcmp(optarg, "threads")) {
719                 /* this is the default */
720             } else {
721                error_report("invalid aio mode `%s'", optarg);
722                exit(EXIT_FAILURE);
723             }
724             break;
725         case QEMU_NBD_OPT_DISCARD:
726             if (seen_discard) {
727                 error_report("--discard can only be specified once");
728                 exit(EXIT_FAILURE);
729             }
730             seen_discard = true;
731             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
732                 error_report("Invalid discard mode `%s'", optarg);
733                 exit(EXIT_FAILURE);
734             }
735             break;
736         case QEMU_NBD_OPT_DETECT_ZEROES:
737             detect_zeroes =
738                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
739                                 optarg,
740                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
741                                 &local_err);
742             if (local_err) {
743                 error_reportf_err(local_err,
744                                   "Failed to parse detect_zeroes mode: ");
745                 exit(EXIT_FAILURE);
746             }
747             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
748                 !(flags & BDRV_O_UNMAP)) {
749                 error_report("setting detect-zeroes to unmap is not allowed "
750                              "without setting discard operation to unmap");
751                 exit(EXIT_FAILURE);
752             }
753             break;
754         case 'b':
755             bindto = optarg;
756             break;
757         case 'p':
758             port = optarg;
759             break;
760         case 'o':
761             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
762                 error_report("Invalid offset '%s'", optarg);
763                 exit(EXIT_FAILURE);
764             }
765             break;
766         case 'l':
767             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
768                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
769                                                   optarg, false);
770                 if (!sn_opts) {
771                     error_report("Failed in parsing snapshot param `%s'",
772                                  optarg);
773                     exit(EXIT_FAILURE);
774                 }
775             } else {
776                 sn_id_or_name = optarg;
777             }
778             /* fall through */
779         case 'r':
780             nbdflags |= NBD_FLAG_READ_ONLY;
781             flags &= ~BDRV_O_RDWR;
782             break;
783         case 'P':
784             warn_report("The '-P' option is deprecated; use --image-opts with "
785                         "a raw device wrapper for subset exports instead");
786             if (qemu_strtoi(optarg, NULL, 0, &partition) < 0 ||
787                 partition < 1 || partition > 8) {
788                 error_report("Invalid partition '%s'", optarg);
789                 exit(EXIT_FAILURE);
790             }
791             break;
792         case 'B':
793             bitmap = optarg;
794             break;
795         case 'k':
796             sockpath = optarg;
797             if (sockpath[0] != '/') {
798                 error_report("socket path must be absolute");
799                 exit(EXIT_FAILURE);
800             }
801             break;
802         case 'd':
803             disconnect = true;
804             break;
805         case 'c':
806             device = optarg;
807             break;
808         case 'e':
809             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
810                 shared < 1) {
811                 error_report("Invalid shared device number '%s'", optarg);
812                 exit(EXIT_FAILURE);
813             }
814             break;
815         case 'f':
816             fmt = optarg;
817             break;
818         case 't':
819             persistent = 1;
820             break;
821         case 'x':
822             export_name = optarg;
823             break;
824         case 'D':
825             export_description = optarg;
826             break;
827         case 'v':
828             verbose = 1;
829             break;
830         case 'V':
831             version(argv[0]);
832             exit(0);
833             break;
834         case 'h':
835             usage(argv[0]);
836             exit(0);
837             break;
838         case '?':
839             error_report("Try `%s --help' for more information.", argv[0]);
840             exit(EXIT_FAILURE);
841         case QEMU_NBD_OPT_OBJECT: {
842             QemuOpts *opts;
843             opts = qemu_opts_parse_noisily(&qemu_object_opts,
844                                            optarg, true);
845             if (!opts) {
846                 exit(EXIT_FAILURE);
847             }
848         }   break;
849         case QEMU_NBD_OPT_TLSCREDS:
850             tlscredsid = optarg;
851             break;
852         case QEMU_NBD_OPT_IMAGE_OPTS:
853             imageOpts = true;
854             break;
855         case 'T':
856             g_free(trace_file);
857             trace_file = trace_opt_parse(optarg);
858             break;
859         case QEMU_NBD_OPT_TLSAUTHZ:
860             tlsauthz = optarg;
861             break;
862         case QEMU_NBD_OPT_FORK:
863             fork_process = true;
864             break;
865         case 'L':
866             list = true;
867             break;
868         }
869     }
870 
871     if (list) {
872         if (argc != optind) {
873             error_report("List mode is incompatible with a file name");
874             exit(EXIT_FAILURE);
875         }
876         if (export_name || export_description || dev_offset || partition ||
877             device || disconnect || fmt || sn_id_or_name || bitmap ||
878             seen_aio || seen_discard || seen_cache) {
879             error_report("List mode is incompatible with per-device settings");
880             exit(EXIT_FAILURE);
881         }
882         if (fork_process) {
883             error_report("List mode is incompatible with forking");
884             exit(EXIT_FAILURE);
885         }
886     } else if ((argc - optind) != 1) {
887         error_report("Invalid number of arguments");
888         error_printf("Try `%s --help' for more information.\n", argv[0]);
889         exit(EXIT_FAILURE);
890     } else if (!export_name) {
891         export_name = "";
892     }
893 
894     qemu_opts_foreach(&qemu_object_opts,
895                       user_creatable_add_opts_foreach,
896                       NULL, &error_fatal);
897 
898     if (!trace_init_backends()) {
899         exit(1);
900     }
901     trace_init_file(trace_file);
902     qemu_set_log(LOG_TRACE);
903 
904     socket_activation = check_socket_activation();
905     if (socket_activation == 0) {
906         setup_address_and_port(&bindto, &port);
907     } else {
908         /* Using socket activation - check user didn't use -p etc. */
909         const char *err_msg = socket_activation_validate_opts(device, sockpath,
910                                                               bindto, port,
911                                                               list);
912         if (err_msg != NULL) {
913             error_report("%s", err_msg);
914             exit(EXIT_FAILURE);
915         }
916 
917         /* qemu-nbd can only listen on a single socket.  */
918         if (socket_activation > 1) {
919             error_report("qemu-nbd does not support socket activation with %s > 1",
920                          "LISTEN_FDS");
921             exit(EXIT_FAILURE);
922         }
923     }
924 
925     if (tlscredsid) {
926         if (sockpath) {
927             error_report("TLS is only supported with IPv4/IPv6");
928             exit(EXIT_FAILURE);
929         }
930         if (device) {
931             error_report("TLS is not supported with a host device");
932             exit(EXIT_FAILURE);
933         }
934         if (tlsauthz && list) {
935             error_report("TLS authorization is incompatible with export list");
936             exit(EXIT_FAILURE);
937         }
938         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
939         if (local_err) {
940             error_report("Failed to get TLS creds %s",
941                          error_get_pretty(local_err));
942             exit(EXIT_FAILURE);
943         }
944     } else {
945         if (tlsauthz) {
946             error_report("--tls-authz is not permitted without --tls-creds");
947             exit(EXIT_FAILURE);
948         }
949     }
950 
951     if (list) {
952         saddr = nbd_build_socket_address(sockpath, bindto, port);
953         return qemu_nbd_client_list(saddr, tlscreds, bindto);
954     }
955 
956 #if !HAVE_NBD_DEVICE
957     if (disconnect || device) {
958         error_report("Kernel /dev/nbdN support not available");
959         exit(EXIT_FAILURE);
960     }
961 #else /* HAVE_NBD_DEVICE */
962     if (disconnect) {
963         int nbdfd = open(argv[optind], O_RDWR);
964         if (nbdfd < 0) {
965             error_report("Cannot open %s: %s", argv[optind],
966                          strerror(errno));
967             exit(EXIT_FAILURE);
968         }
969         nbd_disconnect(nbdfd);
970 
971         close(nbdfd);
972 
973         printf("%s disconnected\n", argv[optind]);
974 
975         return 0;
976     }
977 #endif
978 
979     if ((device && !verbose) || fork_process) {
980         int stderr_fd[2];
981         pid_t pid;
982         int ret;
983 
984         if (qemu_pipe(stderr_fd) < 0) {
985             error_report("Error setting up communication pipe: %s",
986                          strerror(errno));
987             exit(EXIT_FAILURE);
988         }
989 
990         /* Now daemonize, but keep a communication channel open to
991          * print errors and exit with the proper status code.
992          */
993         pid = fork();
994         if (pid < 0) {
995             error_report("Failed to fork: %s", strerror(errno));
996             exit(EXIT_FAILURE);
997         } else if (pid == 0) {
998             close(stderr_fd[0]);
999             ret = qemu_daemon(1, 0);
1000 
1001             /* Temporarily redirect stderr to the parent's pipe...  */
1002             old_stderr = dup(STDERR_FILENO);
1003             dup2(stderr_fd[1], STDERR_FILENO);
1004             if (ret < 0) {
1005                 error_report("Failed to daemonize: %s", strerror(errno));
1006                 exit(EXIT_FAILURE);
1007             }
1008 
1009             /* ... close the descriptor we inherited and go on.  */
1010             close(stderr_fd[1]);
1011         } else {
1012             bool errors = false;
1013             char *buf;
1014 
1015             /* In the parent.  Print error messages from the child until
1016              * it closes the pipe.
1017              */
1018             close(stderr_fd[1]);
1019             buf = g_malloc(1024);
1020             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
1021                 errors = true;
1022                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
1023                 if (ret < 0) {
1024                     exit(EXIT_FAILURE);
1025                 }
1026             }
1027             if (ret < 0) {
1028                 error_report("Cannot read from daemon: %s",
1029                              strerror(errno));
1030                 exit(EXIT_FAILURE);
1031             }
1032 
1033             /* Usually the daemon should not print any message.
1034              * Exit with zero status in that case.
1035              */
1036             exit(errors);
1037         }
1038     }
1039 
1040     if (device != NULL && sockpath == NULL) {
1041         sockpath = g_malloc(128);
1042         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
1043     }
1044 
1045     server = qio_net_listener_new();
1046     if (socket_activation == 0) {
1047         saddr = nbd_build_socket_address(sockpath, bindto, port);
1048         if (qio_net_listener_open_sync(server, saddr, &local_err) < 0) {
1049             object_unref(OBJECT(server));
1050             error_report_err(local_err);
1051             exit(EXIT_FAILURE);
1052         }
1053     } else {
1054         size_t i;
1055         /* See comment in check_socket_activation above. */
1056         for (i = 0; i < socket_activation; i++) {
1057             QIOChannelSocket *sioc;
1058             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
1059                                              &local_err);
1060             if (sioc == NULL) {
1061                 object_unref(OBJECT(server));
1062                 error_report("Failed to use socket activation: %s",
1063                              error_get_pretty(local_err));
1064                 exit(EXIT_FAILURE);
1065             }
1066             qio_net_listener_add(server, sioc);
1067             object_unref(OBJECT(sioc));
1068         }
1069     }
1070 
1071     if (qemu_init_main_loop(&local_err)) {
1072         error_report_err(local_err);
1073         exit(EXIT_FAILURE);
1074     }
1075     bdrv_init();
1076     atexit(qemu_nbd_shutdown);
1077 
1078     srcpath = argv[optind];
1079     if (imageOpts) {
1080         QemuOpts *opts;
1081         if (fmt) {
1082             error_report("--image-opts and -f are mutually exclusive");
1083             exit(EXIT_FAILURE);
1084         }
1085         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
1086         if (!opts) {
1087             qemu_opts_reset(&file_opts);
1088             exit(EXIT_FAILURE);
1089         }
1090         options = qemu_opts_to_qdict(opts, NULL);
1091         qemu_opts_reset(&file_opts);
1092         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1093     } else {
1094         if (fmt) {
1095             options = qdict_new();
1096             qdict_put_str(options, "driver", fmt);
1097         }
1098         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
1099     }
1100 
1101     if (!blk) {
1102         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1103                           argv[optind]);
1104         exit(EXIT_FAILURE);
1105     }
1106     bs = blk_bs(blk);
1107 
1108     blk_set_enable_write_cache(blk, !writethrough);
1109 
1110     if (sn_opts) {
1111         ret = bdrv_snapshot_load_tmp(bs,
1112                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1113                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1114                                      &local_err);
1115     } else if (sn_id_or_name) {
1116         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1117                                                    &local_err);
1118     }
1119     if (ret < 0) {
1120         error_reportf_err(local_err, "Failed to load snapshot: ");
1121         exit(EXIT_FAILURE);
1122     }
1123 
1124     bs->detect_zeroes = detect_zeroes;
1125     fd_size = blk_getlength(blk);
1126     if (fd_size < 0) {
1127         error_report("Failed to determine the image length: %s",
1128                      strerror(-fd_size));
1129         exit(EXIT_FAILURE);
1130     }
1131 
1132     if (dev_offset >= fd_size) {
1133         error_report("Offset (%" PRIu64 ") has to be smaller than the image "
1134                      "size (%" PRId64 ")", dev_offset, fd_size);
1135         exit(EXIT_FAILURE);
1136     }
1137     fd_size -= dev_offset;
1138 
1139     if (partition) {
1140         uint64_t limit;
1141 
1142         if (dev_offset) {
1143             error_report("Cannot request partition and offset together");
1144             exit(EXIT_FAILURE);
1145         }
1146         ret = find_partition(blk, partition, &dev_offset, &limit);
1147         if (ret < 0) {
1148             error_report("Could not find partition %d: %s", partition,
1149                          strerror(-ret));
1150             exit(EXIT_FAILURE);
1151         }
1152         /*
1153          * MBR partition limits are (32-bit << 9); this assert lets
1154          * the compiler know that we can't overflow 64 bits.
1155          */
1156         assert(dev_offset + limit >= dev_offset);
1157         if (dev_offset + limit > fd_size) {
1158             error_report("Discovered partition %d at offset %" PRIu64
1159                          " size %" PRIu64 ", but size exceeds file length %"
1160                          PRId64, partition, dev_offset, limit, fd_size);
1161             exit(EXIT_FAILURE);
1162         }
1163         fd_size = limit;
1164     }
1165 
1166     export = nbd_export_new(bs, dev_offset, fd_size, export_name,
1167                             export_description, bitmap, nbdflags,
1168                             nbd_export_closed, writethrough, NULL,
1169                             &error_fatal);
1170 
1171     if (device) {
1172 #if HAVE_NBD_DEVICE
1173         int ret;
1174 
1175         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1176         if (ret != 0) {
1177             error_report("Failed to create client thread: %s", strerror(ret));
1178             exit(EXIT_FAILURE);
1179         }
1180 #endif
1181     } else {
1182         /* Shut up GCC warnings.  */
1183         memset(&client_thread, 0, sizeof(client_thread));
1184     }
1185 
1186     nbd_update_server_watch();
1187 
1188     /* now when the initialization is (almost) complete, chdir("/")
1189      * to free any busy filesystems */
1190     if (chdir("/") < 0) {
1191         error_report("Could not chdir to root directory: %s",
1192                      strerror(errno));
1193         exit(EXIT_FAILURE);
1194     }
1195 
1196     if (fork_process) {
1197         dup2(old_stderr, STDERR_FILENO);
1198         close(old_stderr);
1199     }
1200 
1201     state = RUNNING;
1202     do {
1203         main_loop_wait(false);
1204         if (state == TERMINATE) {
1205             state = TERMINATING;
1206             nbd_export_close(export);
1207             nbd_export_put(export);
1208             export = NULL;
1209         }
1210     } while (state != TERMINATED);
1211 
1212     blk_unref(blk);
1213     if (sockpath) {
1214         unlink(sockpath);
1215     }
1216 
1217     qemu_opts_del(sn_opts);
1218 
1219     if (device) {
1220         void *ret;
1221         pthread_join(client_thread, &ret);
1222         exit(ret != NULL);
1223     } else {
1224         exit(EXIT_SUCCESS);
1225     }
1226 }
1227